Chapter 6 - Transportation and the Environment
While transportation enhances the quality of our lives,
it also generates undesired environmental impacts
that can lead to human health problems and ecological
damage. Overall, most transportation air emissions, such as
carbon monoxide and particulates, have declined since 1980
despite significant increases in U.S. population, Gross
Domestic Product, and vehicle-miles traveled. Only nitrogen
oxides, which contribute to the formation of ground-level
ozone, and ammonia remain above their 1990 level.
|
